CONSENT AND AMENDMENT NUMBER THREE TO
                           LOAN AND SECURITY AGREEMENT
                           ---------------------------


          THIS CONSENT AND AMENDMENT NUMBER THREE TO LOAN AND SECURITY AGREEMENT
(this  "Consent and  Amendment")  is entered into as of September  10, 1997 (but
effective only in accordance  with the terms and conditions of Section 4 of this
Consent and Amendment), by and among FOOTHILL CAPITAL CORPORATION,  a California
corporation  ("Foothill"),   LASERSIGHT  INCORPORATED,  a  Delaware  corporation
("LaserSight"),   LASERSIGHT   TECHNOLOGIES,   INC.,   a  Delaware   corporation
("Technologies"),  MEC HEALTH CARE, INC., a Maryland  corporation  ("MEC"),  LSI
ACQUISITION,   INC.,  a  New  Jersey  corporation  ("LSI"),  LASERSIGHT  CENTERS
INCORPORATED,  a Delaware  corporation  ("Centers"),  and MRF,  INC., a Missouri
corporation  ("MRF,"  together  with  LaserSight,  Technologies,  MEC,  LSI, and
Centers, individually and collectively, jointly and severally, "Borrower"), with
reference to the following facts:

          A. Foothill  and  Borrower  heretofore  have entered into that certain
             Loan and Security Agreement, dated as of March 31, 1997, as amended
             by that  certain  Consent  and  Amendment  Number  One to Loan  and
             Security  Agreement  dated  as of July  28,  1997,  and as  further
             amended by that certain  Consent and  Amendment  Number Two to Loan
             and Security Agreement dated as of August 29, 1997 (as amended, the
             "Loan Agreement");

          B. Borrower has requested that Foothill  consent to the acquisition by
             Borrower of a worldwide,  limited  license in certain U.S.  letters
             patent  and  foreign  patents  from Luis A. Ruiz,  M.D.  and Sergio
             Lenchig  (the  "Transaction")  and to  the  amendment  of the  Loan
             Agreement to permit Borrower to incur the  Indebtedness  associated
             with the acquisition of such patent license rights;

          C. Foothill is willing to consent to the Transactions and to amend the
             Loan  Agreement,  in each case,  in  accordance  with the terms and
             conditions hereof; and

          D. All  capitalized  terms used but not defined  herein shall have the
             meanings ascribed to them in the Loan Agreement, as amended hereby.

          NOW, THEREFORE,  in consideration of the above recitals and the mutual
premises contained herein, Foothill and Borrower hereby agree as follows:
<PAGE>

          1. Amendments to the Loan Agreement.

               a. Section 1.1 of the Loan Agreement hereby is amended to include
the following defined terms:

          "Lenchig" means Sergio Lenchig, an individual.

          "License  Agreement" means that certain License and Royalty Agreement,
     dated as of September 10, 1997, among  Technologies,  Ruiz and Lenchig,  in
     form and substance satisfactory to Foothill.

          "Ruiz" means Luis A. Ruiz, M.D., an individual.

          "Ruiz/Lenchig  Reserve"  means  a  reserve  of  $800,000  against  the
     Borrowing  Base,  which reserve shall remain in effect until the earlier to
     occur of: (i) the indefeasible termination, without any continuing recourse
     of Ruiz or Lenchig  against  Borrower or  liability  of Borrower to Ruiz or
     Lenchig, of the License Agreement, or (ii) Ruiz and Lenchig entering into a
     revised Consent Agreement with Foothill in form and substance acceptable to
     Foothill in its sole  discretion  permitting  the  encumbrance  and further
     assignment  of the rights,  title and  interest of  Technologies  under the
     License Agreement.

               b. Section 1.1 of the Loan  Agreement is hereby amended to revise
the following defined terms:

          "Change of Contract" is amended to read "Change of Control" to correct
     a typographical error.

          "Guarantor"  means,  collectively,  LST Laser,  S.A.  (Costa Rica),  a
     corporation  organized under the laws of Costa Rica, Photomed  Acquisition,
     Inc., a Delaware  corporation,  and  LaserSight  Patents,  Inc., a Delaware
     corporation.

               c. The second  sentence of Section 2.1 (a) of the Loan  Agreement
is hereby amended to read as follows:

          For purposes of this  Agreement,  "Borrowing  Base", as of any date of
          determination, shall mean the result of:

               (x) 80% of Eligible Contract Receivables, minus
               (y) the Ruiz/Lenchig Reserve, if applicable, minus
               (z) the  aggregate  amount of reserves,  if any,  established  by
                   Foothill under Section 2.1(b).
<PAGE>

               d. Section 7.1 of the Loan Agreement hereby is amended to add the
following as a new clause (e):

                  "(e) Indebtedness evidenced by the License Agreement."

               e. Section 7.8 of the Loan  Agreement  hereby is amended to add a
reference to Section  7.1(e) in the Section 7.1  references  in  subsection  (b)
thereof.

          2. Foothill's  Consent.  Foothill hereby consents to the  Transaction,
and agrees  that the  Transactions  shall be deemed not to cause any  Default or
Event of  Default  under the Loan  Agreement,  as amended  by this  Consent  and
Amendment.

          3.  Representations  and Warranties.  Borrower  hereby  represents and
warrants to Foothill that (a) the execution,  delivery,  and performance of this
Consent and Amendment and of the Loan Agreement,  as amended by this Consent and
Amendment,  are within its corporate  powers,  have been duly  authorized by all
necessary  corporate  action,  and are not in contravention of any law, rule, or
regulation,  or any order, judgment,  decree, writ, injunction,  or award of any
arbitrator,  court, or governmental authority, or of the terms of its charter or
bylaws, or of any contract or undertaking to which it is a party or by which any
of its properties  may be bound or affected,  and (b) this Consent and Amendment
and the Loan  Agreement,  as amended by this Consent and  Amendment,  constitute
Borrower's legal, valid, and binding obligation, enforceable against Borrower in
accordance with its terms.

          4.  Conditions  Precedent  to the  Effectiveness  of this  Consent and
Amendment.  The  effectiveness  of this Consent and  Amendment is subject to the
fulfillment,  to the  satisfaction  of Foothill and its counsel,  of each of the
following conditions:

               a. Foothill shall have received each of the following  documents,
duly executed, and each such document shall be in full force and effect:

                  (1) Consent Agreement,  in form and substance  satisfactory to
     Foothill,  executed and  delivered by Ruiz and Lenchig in favor of Foothill
     (the "Ruiz/Lenchig Consent");

               b. Ruiz and Lenchig shall have executed and delivered to Foothill
such additional documents, instruments and agreements as Foothill shall require;

               c.  Foothill  shall  have  received  a  copy,   certified  by  an
appropriate  officer of Technologies  as being true and correct,  of the License
Agreement,  and any other documents or instruments  executed and/or delivered in
connection therewith,  each of which shall be in form and substance satisfactory
to Foothill;
<PAGE>

               d. No  Material  Adverse  Change in the  financial  condition  of
Borrower or in the value of the Collateral shall have occurred;

               e.  The  representations  and  warranties  in  this  Consent  and
Amendment,  the Loan Agreement as amended by this Consent and Amendment, and the
other Loan Documents  shall be true and correct in all respects on and as of the
date  hereof,  as  though  made on such date  (except  to the  extent  that such
representations and warranties relate solely to an earlier date);

               f. No Event of Default  or event  which with the giving of notice
or passage of time would  constitute an Event of Default shall have occurred and
be continuing on the date hereof,  nor shall result from the consummation of the
transactions contemplated herein; and

               g. No injunction,  writ, restraining order, or other order of any
nature prohibiting, directly or indirectly, the consummation of the transactions
contemplated  herein  shall  have  been  issued  and  remain  in  force  by  any
governmental authority against Borrower, Foothill, or any of their Affiliates.

          5. Effect on Loan Agreement.  The Loan  Agreement,  as amended hereby,
shall be and remain in full force and effect in accordance  with its  respective
terms and hereby is ratified  and  confirmed  in all  respects.  The  execution,
delivery,  and  performance of this Consent and Amendment shall not operate as a
waiver of or,  except as expressly set forth  herein,  as an  amendment,  of any
right, power, or remedy of Foothill under the Loan Agreement, as in effect prior
to the date hereof.

          6.  Further  Assurances.   Borrower  shall  execute  and  deliver  all
agreements,  documents,  and instruments,  in form and substance satisfactory to
Foothill,  and take all actions as Foothill may reasonably  request from time to
time, to perfect and maintain the perfection and priority of Foothill's security
interests  in  the   Collateral  and  to  fully   consummate  the   transactions
contemplated under this Consent and Amendment and the Loan Agreement, as amended
by this Consent and Amendment.

          7. Miscellaneous.

               a. Upon the  effectiveness  of this Consent and  Amendment,  each
reference in the Loan  Agreement  to "this  Agreement,"  "hereunder,"  "herein,"
"hereof," or words of like import referring to the Loan Agreement shall mean and
refer to the Loan Agreement as amended by this Consent and Amendment.
<PAGE>

               b. Upon the  effectiveness  of this Consent and  Amendment,  each
reference  in  the  Loan  Documents  to  the  "Loan  Agreement,"   "thereunder,"
"therein,"  "thereof," or words of like import  referring to the Loan  Agreement
shall  mean and refer to the Loan  Agreement  as  amended  by this  Consent  and
Amendment.

               c. This Consent and Amendment  shall be governed by and construed
in accordance with the laws of the State of California.

               d. This  Consent and  Amendment  may be executed in any number of
counterparts,  all of which taken  together  shall  constitute  one and the same
instrument  and any of the parties hereto may execute this Consent and Amendment
by signing any such counterpart.


<PAGE>

          IN WITNESS  WHEREOF,  the parties  hereto have caused this Consent and
Amendment to be duly executed as of the date first written above.

                                          FOOTHILL CAPITAL CORPORATION,
                                          a California corporation


                                          By: /s/ Albert R. Joseph
                                             -----------------------------

                                          Title:  Vice President
                                                 -------------------------



                                          LASERSIGHT INCORPORATED,
                                          a Delaware corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:  Chief Financial Officer
                                                 -------------------------


                                          LASERSIGHT TECHNOLOGIES, INC.,
                                          a Delaware corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:   Vice President
                                                 -------------------------


                                          MEC HEALTH CARE, INC.,
                                          a Maryland corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:  Vice President
                                                 -------------------------

<PAGE>

                                          LSI ACQUISITION, INC.,
                                          a New Jersey corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:  Secretary/Treasurer
                                                --------------------------


                                          LASERSIGHT CENTERS INCORPORATED,
                                          a Delaware corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:   Vice President
                                                 -------------------------


                                          MRF, INC.,
                                          a Missouri corporation


                                          By:  /s/ Gregory L. Wilson
                                              ----------------------------

                                          Title:   Secretary/Treasurer
                                                 -------------------------